package kw.android.AProject;

import android.graphics.Matrix;
import android.graphics.PointF;
import android.util.FloatMath;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;

public class MultiTouch {
	final String TAG = "MultiTouch";
	Matrix matrix;
	Matrix savedMatrix;

	final int NONE = 0;
	final int DRAG = 1;
	final int ZOOM = 2;
	int mode = NONE;

	PointF start;
	PointF mid;
	float oldDist = 1f;
	
	public MultiTouch() {
		matrix = new Matrix();
		savedMatrix = new Matrix();
		start = new PointF();
		mid = new PointF();
	}

	/** 멀티터치 
	 * @param event : MotionEvent
	 * @param view : 터치 적용할 뷰
	 * **/
	public Matrix doMultiTouch(MotionEvent event) {
		switch (event.getAction() & MotionEvent.ACTION_MASK) {
	      case MotionEvent.ACTION_DOWN:
	         savedMatrix.set(matrix);
	         start.set(event.getX(), event.getY());
	         Log.d(TAG, "mode=DRAG");
	         mode = DRAG;
	         break;
	      case MotionEvent.ACTION_POINTER_DOWN:
	         oldDist = spacing(event);
	         Log.d(TAG, "oldDist=" + oldDist);
	         if (oldDist > 10f) {
	            savedMatrix.set(matrix);
	            midPoint(mid, event);
	            mode = ZOOM;
	            Log.d(TAG, "mode=ZOOM");
	         }
	         break;
	      case MotionEvent.ACTION_UP:
	      case MotionEvent.ACTION_POINTER_UP:
	         mode = NONE;
	         Log.d(TAG, "mode=NONE");
	         break;
	      case MotionEvent.ACTION_MOVE:
	         if (mode == DRAG) {
	            // ...
	            matrix.set(savedMatrix);
	            matrix.postTranslate(event.getX() - start.x,
	                  event.getY() - start.y);
	         }
	         else if (mode == ZOOM) {
	            float newDist = spacing(event);
	            Log.d(TAG, "newDist=" + newDist);
	            if (newDist > 10f) {
	               matrix.set(savedMatrix);
	               float scale = newDist / oldDist;
	               matrix.postScale(scale, scale, mid.x, mid.y);
	            }
	         }
	         break;
	      }

		return matrix;
//		((ImageView)view).setImageMatrix(matrix);	      
	}
	
	/** Determine the space between the first two fingers */
	public float spacing(MotionEvent event) {
		float x = event.getX(0) - event.getX(1);
		float y = event.getY(0) - event.getY(1);
		return FloatMath.sqrt(x * x + y * y);
	}

	/** Calculate the mid point of the first two fingers */
	private void midPoint(PointF point, MotionEvent event) {
		float x = event.getX(0) + event.getX(1);
		float y = event.getY(0) + event.getY(1);
		point.set(x / 2, y / 2);
	}

	/** Show an event in the LogCat view, for debugging */
	public void dumpEvent(MotionEvent event) {
		String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE",
				"POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" };
		StringBuilder sb = new StringBuilder();
		int action = event.getAction();
		int actionCode = action & MotionEvent.ACTION_MASK;
		sb.append("event ACTION_").append(names[actionCode]);
		if (actionCode == MotionEvent.ACTION_POINTER_DOWN
				|| actionCode == MotionEvent.ACTION_POINTER_UP) {
			sb.append("(pid ").append(
					action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
			sb.append(")");
		}
		sb.append("[");
		for (int i = 0; i < event.getPointerCount(); i++) {
			sb.append("#").append(i);
			sb.append("(pid ").append(event.getPointerId(i));
			sb.append(")=").append((int) event.getX(i));
			sb.append(",").append((int) event.getY(i));
			if (i + 1 < event.getPointerCount())
				sb.append(";");
		}
		sb.append("]");
		Log.d(TAG, sb.toString());
	}

}
